Isotropic rotation in amphidynamic crystals of stacked carbazole-based rotors featuring halogen-bonded stators.

Liquid-like dynamics of a covalent 1,4-phenylene rotator have been unveiled in 1 with a brominated stator showing type-II halogen bonds. This singular rotation is favored by synergistic molecular changes in stacked molecules, according to VT solid state NMR,1 H T1 relaxometry and VT X-ray experiments of this highly crystalline compound.